Objective To compare the spine intensity modulated radiation therapy (IMRT) and the conventional radiation therapy on the beagle spinal cord neurons,in order to prove the biological safety of IMRT of the spinal cord.Methods Twelve selected purebred beagles were randomly divided into 2 groups.A beagle clinical model of tumor was mimiced in the ninth and tenth thoracic vertebrae.Then the beagles were irradiated by 2 different models of intensity modulated radiotherapy and conventional radiation therapy,with the total irradiation doses of 50 and 70 Gy.The samples of spinal cord were taken out from the same position of the nine and tenth thoracic vertebrae at the third month after radiation.All the samples were observed by the electron microscope,and the Fas and HSP70 expression in spinal cord neurons were evaluated by immunohistochemistry method.Terminal deoxynucleatidyl transferase mediated dUTP nick and labeling (TUNEL) technique was used to examine the apoptotic cells in the spinal cord.Results The neurons in the spinal cord of IMRT group were mainly reversible injury,and those in the conventional radiation therapy were mainly apoptosis.Compared with the conventional radiation therapy group [50 Gy group,(7.3±1.1)% ;70 Gy group,(11.3 ±.4)%],the apoptosis rate of the spinal cord neurons of the intensity modulated radiotherapy group[50 Gy group,(1.2 ±0.7)%;70 Gy group(2.5 ±0.8)%] was much lower[(50 Gy group,t＝0.022,P＜0.05;70 Gy group,t＝0.017,P＜0.05)].The expression levels of Fas in the IMPT group(50 Gy group,4.6 ±0.8;70 Gy group,7.4 ±1.1)were also much lowerthan those in the other group(50 Gy group,15.1 4-6.4;70 Gy group,19.3 ±7.6.50 Gy group,t＝0.231,P＜0.05;70 Gy group,t:0.457,P＜0.05),while the expression levels of HSP70 in the IMPT group(50 Gy group,9.1 ±0.8;70 Gy group,7.3±1.4)were much higher than those in the conventional radiation therapy group(50 Gy group,2.1 ±0.9;70 Gy group,1.7±0.3;50 Gy group,t＝0.153,P＜0.05;70 Gy group,t＝0.223,P＜0.05).The expression of Fas/HSP70 was positively correlated with the apoptosis rate of the spinal cord neurons(r＝0.996,t＝1.14.P＜0.05).Conclusions The late radiotherapy response of the spinal cord neurons was obviously observed on the third month.Comparison of the morphology and apoptosis rate of the spinal cord neurons after radiotherapy,the expression of Fas and HSP70 indicated that the biological safety in the 1MRT might be much better than that the conventional radiation therapy.

OBJECTIVETo explore whether there are gene mutations of Tolloid-like 1 (TLL-1) gene in Chinese patients with sporadic congenital heart disease (CHD).

METHODSOne hundred and fifteen patients with sporadic CHD were selected as CHD group. One hundred and two age and gender-matched healthy people were recruited as control group. After amplifying the exon 10 of the TLL-1 gene by polymerase chain reaction, the polymerase chain reaction products were purified, sequenced and analyzed in order to investigate the TLL-1 gene mutation.

RESULTSAn insertion mutation of base A in the exon 10 of TLL-1 gene was identified in 7 out of 115 CHD patients, including 3 patients with atrial septal defect, 2 patients with ventricular septal defect, 1 patients with patent ductus arteriosus and 1 patients with complex CHD, the total mutation rate was 6.1% in CHD group and 0 in control group (P < 0.01).

CONCLUSIONSTLL-1 gene mutation with an insertion mutation of base A in exon 10 is often in Chinese patients with various CHD. The underlying pathogenesis between TLL-1 gene mutation and occurrence of congenital heart disease in Chinese people remains unclear and warrants further investigations.

Adolescent ; Adult ; Aged ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Case-Control Studies ; Child ; Child, Preschool ; Exons ; Female ; Heart Defects, Congenital ; genetics ; Humans ; Male ; Middle Aged ; Mutagenesis, Insertional ; Pedigree ; Tolloid-Like Metalloproteinases ; genetics ; Young Adult